Field of the Disclosure
Examples of the present disclosure are related to systems and methods for lighting fixtures. More particularly, embodiments disclose lighting fixtures utilizing bends in heat sink device comprised of metal-core PCB (MCPCB) for thermal, mechanical, and/or optical controls.
Background
Controlled environment agriculture, especially vertical farming is becoming more prevalent in the US and around the world. Vertical farming relies on light fixtures to illuminate a plant canopy. The light fixtures uniformly distribute radiant flux over the plant canopy, while removing heat from light sources (typically LEDs). The light fixtures' efficacy and cost directly impacts the operational expenses associated with vertical farming. As fixture height directly influences a number of vertical layers within a growth volume, it is important to minimize a form factor or vertical height of the fixture
Operating higher-powered lights in a vertical growth is more costly than utilizing free sunlight in greenhouses or field-grown. To overcome these costs, vertical farming must have increased yields, shorter growth cycles, more consistent product, less water usage, reduce farm to plate timeframe, higher nutrient content, and other tangible advantages.
Although light emitting diodes (LEDs) used in vertical farming are more efficient than traditional higher-powered lights, their manufacturing costs are also higher. Additionally, their performance is negatively impacted with thermal rise. The terminal rise requires the light fixtures to dissipate heat more efficiently. This generated heat causes issues such as decreased longevity and lower fixture efficacy. To circumvent the requirements to dissipate the heat, some manufacturers have built complex LED fixtures. This has led to conventional LED fixtures being coupled to heat sinks.
Conventional LED fixtures utilize LEDs that are positioned on a printed circuit board. PCB substrates may be made of different materials such as FR4, Aluminum, copper, etc. In most application, an insulative substrate is necessary such as FR4. In higher powered applications, a highly thermally conductive substrate is desired. For LEDs, thermal dissipation is paramount and therefore Aluminum substrates are often utilized. When metal is used as the substrate, the term metal core printed circuit board is used or more commonly MCPCB.
Conventionally, a linear MCPCB is coupled to the heatsink to dissipate generated heat, wherein the linear heatsink may include fins to dissipate heat. However, the fins may act as heat blocks and prevent air from reaching the hot surface. Thus, linear heatsinks with fins may lead to inefficient thermal transfer or increased thermal resistance between the heat source (LEDs) and the environment. Moreover, process to affix the LEDs to the MCPCB and then to couple the MCPCB to the heat sink requires time and resources. This can be an arduous, time consuming, and costly task.
Accordingly, needs exist for more effective and efficient systems and methods for light fixtures with LEDS integrated directly into MCPCB, wherein the MCPCB includes one or more bends for mechanical strength, aesthetics, thermal controls, and/or optical controls.